Due to concerns over air pollution and global climate change as well as general highway safety, most jurisdictions in the United States now require regular vehicle inspections. In addition to checking vehicles for obvious items such as brakes, lights, mirrors, and tire tread, many jurisdictions also perform emission analysis of vehicle exhaust. In addition to checking for visible smoke, emission tests are now typically performed using automated sensing equipment that check for hydrocarbons, carbon monoxide, nitric oxide, and other possible emissions. This equipment in many cases is connected directly to a jurisdiction-owned computer system that allows the jurisdiction to obtain a complete inspection record including the vehicle identification information and relevant emissions data for that vehicle.
Automated inspection systems allow the state to maintain statistics on vehicles in the jurisdiction and in theory also reduce fraudulent inspection practices—that is, passing vehicles without actually confirming that they should be passed or in some cases ignoring detected violations.
Inspection criteria and fees are usually set by legislation and/or agency order. Therefore, inspection stations are limited as to what they can charge for performing inspections and are thus incentivized to perform them as quickly as possible to maximize total revenue. This may lead to sloppy and even fraudulent practices despite the use of automated systems.